Related Experiment Video
Updated: Jun 16, 2026

Expression of Recombinant Proteins in the Methylotrophic Yeast Pichia pastoris
Published on: February 25, 2010
Unconventional secretion of Pichia pastoris Acb1 is dependent on GRASP protein, peroxisomal functions, and
Ravi Manjithaya1, Christophe Anjard, William F Loomis
1Section of Molecular Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA.
Abstract:
In contrast to the enormous advances made regarding mechanisms of conventional protein secretion, mechanistic insights into the unconventional secretion of proteins are lacking. Acyl coenzyme A (CoA)-binding protein (ACBP; AcbA in Dictyostelium discoideum), an unconventionally secreted protein, is dependent on Golgi reassembly and stacking protein (GRASP) for its secretion. We discovered, surprisingly, that the secretion, processing, and function of an AcbA-derived peptide, SDF-2, are conserved between the yeast Pichia pastoris and D. discoideum. We show that in yeast, the secretion of SDF-2-like activity is GRASP dependent, triggered by nitrogen starvation, and requires autophagy proteins as well as medium-chain fatty acyl CoA generated by peroxisomes. Additionally, a phospholipase D implicated in soluble N-ethyl-maleimide sensitive fusion protein attachment protein receptor-mediated vesicle fusion at the plasma membrane is necessary, but neither peroxisome turnover nor fusion between autophagosomes and the vacuole is essential. Moreover, yeast Acb1 and several proteins required for its secretion are necessary for sporulation in P. pastoris. Our findings implicate currently unknown, evolutionarily conserved pathways in unconventional secretion.
Related Concept Videos
Autophagy
An autophagic pathway consists of a series of signaling events activated in response to diverse stress and physiological conditions such as food deprivation,...
Protein Import into the Peroxisomes
Peroxisomal Protein Import:
Peroxisomes lack the genetic machinery required to code for their own proteins. Hence, most peroxisomal membrane, lumenal and transmembrane proteins are synthesized in the cytoplasm or ER and transported to the peroxisome...
Pinching-off of Coated Vesicles
Overview of Secretory Vesicles
Various proteins regulate the aggregation of molecules inside the secretory vesicles. Chromogranins...
Export of Misfolded Proteins out of the ER
Protein Transport to the Outer Chloroplast Membrane
Two models describe the mechanism of precursor recognition and entry across the outer membrane through the TOC complex. Model 1 suggests the newly synthesized precursor binds to the TOC receptor 159 and forms a complex.

